Note 10 - Subsequent Events (Details Textual) $ in Millions		3 Months Ended	9 Months Ended
	Nov. 12, 2019 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2019 USD ($)
Financial Covenants, Minimum Current Ratio			1
Financial Covenants, Total Debt to EBITDAX Ratio			3.5
Line of Credit [Member]
Financial Covenants, Minimum Current Ratio		1
Line of Credit Facility, Current Borrowing Capacity		$ 207.5	$ 207.5
Line of Credit [Member] | Second Lien Credit Facility [Member] | Subsequent Event [Member]
Financial Covenants, Minimum Current Ratio	1
Line of Credit Facility, Maximum Borrowing Capacity	$ 100.0
Line of Credit, Default, Minimum Interest Rate	3.00%
Debt Instrument, Original Issue Discount	3.50%
Debt Instrument, Collateral Eligible, Minimum Percent of PV-9 Proven Reserves	90.00%
Debt Instrument, Collateral Eligible, Minimum Percent of PV-9 Required PDP Reserves	95.00%
Financial Covenants, Total Debt to EBITDAX Ratio	4
Financial Covenants, Minimum Asset Coverage Ratio in Year One	1.25
Financial Covenants, Minimum Asset Coverage Ratio in Year Two	1.45
Financial Covenants, Minimum Asset Coverage Ratio Thereafter	1.55
Debt Instrument Covenants, Maximum Aggregate Acquisition Expenses Included in Determining EBITDAX	$ 2.0
Debt Instrument Covenants, Maxmimum Aggregate Extraordinary Expenses Included in Determining EBITDAX	$ 1.0
Properties in Reeves Country Texas [Member]
Number of Non-operated Properties		2	2
Properties in Reeves Country Texas and South Texas Asset [Member]
Proceeds from Sale of Property, Plant, and Equipment, Total			$ 7.9